What a great thread. Not suprised it's been picked up by a national newspaper.
How can you tell the celebs? Well, the famous ones you should recognise, the less famous ones will tell you!
I'm form the flight deck, so my expereince of dealing with them is limited. But one thing I found when flying for Virgin Atalntic was that it seemd to be the airline of choice for a lot of minor celebs, not because of it's image but because not having a first class, the 'celebs' could sit in the posh bit of the aircraft and not have to pay first class prices. I don't remeber one LA trip without some celeb causing a fuss.